See trough walls

How can I see trough walls like in the sims.
(dynamic change of mesh visibility)

Sphere Linetrace to mouse Cursor and make every Wall invisible you hit. Or Trace from each Sim towards the Camera. Another Option is to use Sphere mask or Opacity Masks inside the Material in addition to have a smoother Blending.

Handle like you want but the principle stays the same. Good Luck mate =)